Storage trays for holding papers, bills, scrap paper, documents, stationery and the like are very well known. These kinds of storage trays may be classified into two general styles: papers sit vertically in the tray, or papers lay horizontally in the tray. Horizontal trays are generally preferred when it is important to avoid bends or creases in papers, such as raised letterhead stationery, or relatively large sized papers, such as DIN size A3 paper. Vertical trays are generally preferred when it is desired that the storage tray should occupy as little space as possible on a desk.
Horizontal trays are configured to sit horizontally on a desk or other support surface, and cannot generally be converted into a tray for vertical storage of papers, without awkwardly propping or otherwise supporting the tray in the vertical position. The converse is also true for vertical trays which cannot conveniently be converted into horizontal trays without the papers falling out of the tray, for example.